£42 METALLURGY OF CAST IKON.
that can exist in the physical qualities of cast iron due to variations in the pouring temperatures, must perceive its importance.
The first cast of the test bars,, also the chill and fluidity test pieces, are seen at Fig*. 131, page 541. The patterns and core boxes used are shown in Figs. 132 to 136. At Fig. 137 is seen one of the malleable iron flasks used for making the green sand bars from the mould boards seen in Figs. 133 and 134, pages 544 and 546. The flask, as shown, is clamped and upended ready for lowering into the casting pit, to be placed as seen at K, Fig. 138, page 550. The making of all these patterns, core boxes, and flasks was under the supervision of Dr. R. Moldenke while engaged as metallurgist with McConway & Torlcy of Pittsburgh and who donated them to the committee in the interest of the trade. Doctor Moldenke is to be credited with having done most of the work in making the patterns and fitting up the flasks.
The floor space* required for casting a full set of these bars was eight feet wide by eighteen feet long, dug out to make a pit about three feet deep. The time required to mould and cast a full set as shown in Fig. 131 involved about thirty days' labor. The first set was made under the author's close supervision; in fact, he did considerable of the work. After the pit was dug out a level floor was made in the bottom and all the green sand moulds and cores were set in place after the manner shown in Fig. 138. These set, sand was rammed around all the flasks and cores up to the level of K and W, Fig. 140, page 552, after which a double row of vents was made down each side of the cores and flasks. A bed of fine cinders was next noted to any degree the variationsin diameter. (See next chapter.)ards, see pages 573, 577 and 571;.n page 573, which show that test bars should not be smaller than \y* inches in diameter, and cast on end, us such will tfive truer results than the [J4™inch round bar in general practice, especially in making comparison <>i; the widest ranges in grades.temper '' or damp- ,| |